Odd chemicals turn up in drinking water

Trace amounts of sex hormones, prescription drugs, flame retardants and herbicides are being detected in treated drinking water pumped to more than 7 million people in Chicago and its suburbs.

In the latest round of testing prompted by a 2008 Tribune investigation, city officials discovered that more than two dozen pharmaceutical drugs and other unregulated chemicals pass through Chicago's massive treatment plants.

Little is known about potential health effects from drinking drug-contaminated water, but scientists and regulators increasingly are concerned about long-term exposure, even at very low levels.

"We need to start addressing the cumulative effects that these low-dose exposures could be having on people," said Thomas Burke, associate dean of the Johns Hopkins Bloomberg School of Public Health.

"There are no quick solutions," said Burke, who chaired a National Academy of Sciences committee that called for a dramatic overhaul of the way the U.S. regulates toxic chemicals. "But we need a new approach that is more responsive to emerging science."

Like other cities, Chicago must notify the public if its drinking water contains regulated contaminants, including lead, pesticides and harmful bacteria. There is no such requirement if pharmaceuticals and other unregulated substances are detected.

City officials were prompted to start testing for the substances after the Tribune found trace amounts of pharmaceuticals, residue from personal care products and unregulated industrial chemicals in local tap water. Substances found in the city's latest tests include the sex hormones testosterone and progesterone; gemfibrozil, a prescription cholesterol-fighting drug; and DEET, the active ingredient in bug spray.

The tests also found perfluorooctane sulfonate, an ingredient in Scotchgard stain-fighting coatings; bisphenol A, a hormone-like plastics additive; and tris (2-butoxyethyl) phosphate, a flame retardant chemical.

"Our very awareness of trace amounts of these chemicals comes in large part because we are aggressively conducting research on water quality and safety," said Tom LaPorte, a spokesman for the Chicago Department of Water Management.

Drugs end up in drinking water after people take medicines and residue passes through their bodies down the toilet. Conventional sewage and water treatment filters out some of the substances, or at least reduces the concentrations, but studies have found that small amounts still get through.

Although treated sewage from the Chicago area drains away from Lake Michigan, more than 300 other cities discharge treated waste and untreated sewage overflows into the lake and its tributaries, according to the EPA.

"Exposure to some of these chemicals … is cause for consternation for people and concern over fish and wildlife impacts," said Rebecca Klaper, a researcher at the University of Wisconsin-Milwaukee who studies the Great Lakes.

The EPA's position is that it doesn't yet have enough evidence to limit pharmaceuticals and many other unregulated chemicals in drinking water. Water officials say not enough is known to justify spending millions of taxpayer dollars to upgrade treatment plants.

What you can do

Drug disposal: The detection of pharmaceuticals in water has prompted new advice about how to properly dispose of unused medicine. The Illinois EPA recommends taking it to collection events for household hazardous waste. If that is not practical, you can place unused drugs in the trash after grinding them up and mixing them with coffee grounds or cat box filler so they can't be stolen. Questions? Email the agency at EPA.Meds.Mail@Illinois.gov.

Filters: Conventional water treatment does not screen out many unregulated contaminants, but some household filters can help. Water filtration products are certified by NSF International, a nonprofit group. Visit nsf.org.